1. Field of the Invention
The present invention relates to flip-chip bonding parts used in the bonding of a semiconductor device, flip-chip bonding confirmation parts used in a semiconductor device with a daisy-chain type pattern, and a flip-chip bonding method.
2. Prior Art
For example, semiconductor devices with daisy-chain type patterns are manufactured by bonding a chip directly to a substrate, and then injecting an underfilling between the two. On the substrate side, patterns and pads are formed on a printed substrate or a ceramic substrate; and on the chip side, pads are formed on a silicon chip. Since the substrate and chip are opaque, the patterns and pads on the substrate and chip cannot be observed by transmitted light.
The above-described semiconductor devices having daisy-chain type patterns are universally known as disclosed in, for example, Japanese Patent Application Laid-Open (Kokai) No. H5-29546, and nave a pattern system in which the respective pads on the substrate and the respective pads on the chip are connected between two terminals used for confirmation of electrical continuity (formed on the substrate) so that a chain is formed when the substrate and chip are bonded with the pad pattern formed on the substrate and the pad pattern formed on the chip superimposed.
Bonding of a semiconductor device provided with a daisy-chain type pattern is accomplished by the process shown in FIG. 5.
As seen from FIG. 5(a), a substrate 1 is held by a substrate chuck 2 with the pattern and pad surfaces of the substrate 1 facing upward, and a chip 3 is held by a chip chuck 4 with the pattern and pad surfaces of the chip 3 facing downward; and the chip 3 is positioned above the substrate 1. Next, as shown in FIG. 5(b), an optical probe 5 which has detection parts on its upper and lower surfaces is moved into the space between the substrate 1 and chip 3 in the direction indicated by arrow A, and the respective patterns and pads of the substrate 1 and chip 3 are detected by the optical probe 5. Then, the substrate chuck 2 and chip chuck 4 are moved relative to each other so that the substrate 1 and chip 3 are leveled and aligned.
Afterward, as shown in FIG. 5(c), the optical probe 5 is moved away from the space between the substrate 1 and chip 3 in the direction indicated by arrow B. Then, as shown in FIG. 5(d), the substrate chuck 2 is raised, so that the substrate 1 and chip 3 are bonded. Thereafter, as shown in FIG. 5(e), the substrate chuck 2 is lowered, thus finishing the bonding of the substrate 1 and chip 3.
The probe described in Japanese Patent Application Publication (Kokoku) No. H6-28272 may be cited as an example of the optical probe 5.
The confirmation of bonding precision in the above semiconductor device is accomplished in the following manner: a confirmation element which is either the substrate or chip and consists of a transparent glass is bonded, this bonded sample is removed from the bonding apparatus, and then positional deviations of the patterns and pads on the substrate and chip are measured by a length-measuring device from the glass side. Thus, since it is necessary to remove the bonded confirmation element from the bonding apparatus in order to perform measurements, rapid confirmation of the bonding precision is impossible.
Furthermore, in conventional confirmation elements which are transparent only on one side, no daisy-chain type pattern is provided, and the bonded semiconductor device used for confirmation is opaque, thus rendering it impossible to confirm an electrical continuity. As a result, confirmation of electrical continuity requires the inspection of an actual opaque semiconductor device, and the confirmation of bonding precision and confirmation of electrical continuity must be performed separately. Furthermore, since the device is opaque, the internal portions of the bonded parts cannot be checked; and the underfilling injection conditions when a sealing material is injected between the substrate and chip in a subsequent process cannot be observed.